Method and apparatus for transmitting information, and reproducing apparatus, receiving apparatus and recording medium for the information, and transmission data thereof

ABSTRACT

An output control (OPC) information is recorded on the magnetic tape  1  in conjunction with an MPEG stream. The OPC information is composed of two bits and is extracted from a reproduced signal by the output control circuit  9  and controls the digital interface (D. I/F)  7  and the switch circuit  11 . In case a first bit of the OPC information is “0”, the output control circuit  9  makes the D. I/F  7  enabled and permits the output of a digital signal. In a case of “1”, the output control circuit  9  prohibits to output the digital signal. Further, when the second bit of the OPC information is “0”, the output control circuit  9  turns the switch circuit  11  off, preventing the output of an analog component signal. In case its “1”, the output control circuit  9  permits the output of the analog component signal.

This application is a continuing application of co-pending applicationSer. No. 09/713,260, filed on Nov. 16, 2000, and for which priority isclaimed under 35 U.S.C. § 120; and this application claims priority ofapplication No. 11-335501/1999 filed in Japan on Nov. 26, 1999 andapplication No. 2000-14671/2000 filed in Japan on Jan. 24, 2000 under 35U.S.C. § 119; the entire contents of all are hereby incorporated byreference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a method and an apparatus fortransmitting information, and a reproducing apparatus, a receivingapparatus and a recording medium for the information, and transmissiondata thereof, particularly, relates to a transmission for preventingdigital information recorded on a recording medium in a packet anddigital information transmitted through a broadcasting ortelecommunications from illegal duplication or copying, such that amethod and an apparatus for transmitting information, and a reproducingapparatus, a receiving apparatus and a recording medium for theinformation, and transmission data thereof, which performs recording andreproducing.

2. Description of the Related Art

In an apparatus, which can copy digitally, such as a digital audio tape(DAT) recorder, the serial copy management system (SCMS), which permitscopying from an original recording once, is well known as a copy guardtechnology for preventing infringement of copyright such that illegallycopying down from a recording medium prerecorded with information intoanother recording medium. The SCMS system controls copying by using acopy prohibiting/permitting flag, which is contained in a digital audiointerface signal.

Further, the copy generation management system (CGMS) is well known as acopy control system, which controls copying down from a recording mediumrecorded with a video signal into another recording medium. The CGMSsystem transfers two bits of a copy generation control signal. Arecording apparatus of the system is organized such that copying ispermitted, in a case that a value of a two bit signal is “00”. In a caseof “10”, copying is permitted once. In a case of “11”, copying isprohibited. Furthermore, in a case of “10”, the system converts it into“11” automatically and records just one time.

Moreover, in a field of a VTR (Video Tape Recorder) or a DVD (DigitalVersatile Disk), recording and reproducing apparatuses such as disclosedin the Japanese Patent Laid-open Publications 61-201586/1986 and9-83936/1997 are also well known. These apparatuses certify an apparatusor a device related and transfer a scramble key such that each apparatushas an inherent ID and makes a video signal deform by using the ID andrandom numbers and records by inserting the random numbers in a verticalblanking period when recording, and further, the apparatus restores thevideo signal by using the random numbers read out from the verticalblanking period and the ID when reproducing.

An environment, which is for developing a recording and reproducingapparatus with considering a copyrighter by using the SCMS and CGMSsystems and further a macro-vision signal, is getting regulated.However, in a case of a digital transmission, some copyrighters worryabout appropriation by a computer. In a case of an analog transmission,other copyrighters worry about casual copying by a current apparatus orequipment. Furthermore, some of current copyrighters mention that anenvironment for selling prerecorded software in high definition is notprepared yet.

SUMMARY OF THE INVENTION

Accordingly, in consideration of the above-mentioned problems of theprior art, an object of the present invention is to provide a method andan apparatus for transmitting information, and a reproducing apparatus,a receiving apparatus and a recording medium for the information, andtransmission data thereof, which can prevent illegal copying moreeffectively with being able to designate an output format by acopyrighter.

In order to achieve the above object, the present invention provides,according to a first aspect thereof, a method for transmittinginformation to an outputting apparatus, which can converts aninformation in a transport packet into at least one signal format out ofa plurality of signal formats being different from each other and outputthe converted information, the method is characterized in that a flagfor designating a signal format to be outputted by the outputtingapparatus is transmitted with being included in the information.

According to a second aspect of the present invention, there provided anapparatus for transmitting information with generating an information tobe transmitted to an outputting apparatus, which can convert informationin a transport packet into at least one signal format out of a pluralityof signal formats being different from each other and output theconverted information, the apparatus is characterized in that a flag fordesignating a signal format to be outputted by the outputting apparatusis transmitted with being included in the information.

According to a third aspect of the present invention, there is provideda reproducing apparatus having a plurality of outputting sections, whichconverts an information reproduced from a recording medium into aplurality of signal formats being different from each other and outputsrespective signal formats, wherein the recording medium is previouslyrecorded with a flag, which designates an output signal format from theplurality of outputting sections, the reproducing apparatus comprising:extracting means for extracting the flag from a reproduced signal fromthe recording medium; controlling means for activating an outputtingsection, which outputs a designated output signal format out of theplurality of outputting sections in accordance with the flag andcontrols the other outputting sections to prohibit to be activated.

According to a fourth aspect of the present invention, there provided areceiving apparatus having a plurality of outputting sections, whichconverts a signal information received through a predeterminedtransmission line into a plurality of signal formats being differentfrom each other and outputs respective signal formats, wherein thesignal information received through the predetermined transmission lineis previously multiplexed with a flag, which designates an output signalformat from the plurality of outputting sections, the receivingapparatus comprising: extracting means for extracting the flag from thesignal information received through the predetermined transmission line;and controlling means for activating an outputting section, which outputa designated output signal format out of the plurality of outputtingsections in accordance with the flag and controls the other outputtingsections to prohibit to be activated.

According to a fifth aspect of the present invention, there provided arecording medium, which is recorded with at least a video information inconjunction with an auxiliary information on each track of apredetermined length in a unit of a data block of a fixed length, therecording medium is further characterized in that a flag for designatinga signal format to be outputted by an outputting apparatus of the videoinformation is recorded in the data block.

According to a sixth aspect of the present invention, there provided atransmission data, which is transmitted with multiplexing at least avideo information by a transport packet and with constituting atransport stream, the transmission data is further characterized in thata flag for designating a signal format to be outputted by an outputtingapparatus of the video information is included in the transport stream.

Other object and further features of the present invention will beapparent from the following detailed description when read inconjunction with the accompanying drawings.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a block diagram of a reproducing apparatus according to afirst embodiment of the present invention.

FIG. 2 shows an exemplary format of a recording track on a magnetic tapeshown in FIG. 1.

FIG. 3 shows an exemplary format of a sync-block in a main code areashown in FIG. 2.

FIG. 4 shows a configuration of flags allocated in two bytes of a mainheader area shown in FIG. 3.

FIG. 5 shows an exemplary format of a transmission signal according to asecond embodiment of the present invention.

FIG. 6 shows PMT (Program Map Table) syntax in accordance with the MPEG(Moving Picture Experts Group) system standard.

FIG. 7 shows syntax of an OPC (OutPut Control) descriptor to betransmitted according to the second embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First Embodiment

This embodiment is explained with referring to the D-VHS (Digital-VideoHome System: registered trademark of Victor Company of Japan, Ltd.)system, which can record and reproduce video and audio information in adigital signal format.

FIG. 1 is a block diagram of a reproducing apparatus according to afirst embodiment of the present invention.

FIG. 2 shows an exemplary format of a recording track on a magnetic tapeshown in FIG. 1.

In FIG. 1, a reproducing apparatus comprises a magnetic tape 1, a rotaryhead 2, a head amplifier 3, an equalizer 4, a demodulator 5, an errorcorrection code (ECC) circuit 6, a digital interface (D. I/F) 7, an MPEG(Moving Picture Experts Group) decoder 8, an output control circuit 9,an NTSC (National Television System Committee) encoder 10 and a switchcircuit 11. The magnetic tape 1 is one embodiment of a recording mediumaccording to the present invention and is previously recorded with adesired information in conjunction with an audio information in adigital signal format on a digital signal recording track having alongitudinal axis slanted to a longitudinal direction of the magnetictape 1. Further, an output control (OPC) information is also recorded ona digital signal recording track in the magnetic tape 1.

As shown in FIG. 2, a digital signal recording track formed on themagnetic tape 1 is composed of a certain amount of data areas called async-block (SB). A plurality of SBs is allocated on a digital signalrecording track on the magnetic tape 1 in accordance with scanning bythe rotary head 2. In other words, as shown in FIG. 2, a track format ona digital signal recording track comprises two sync-blocks of a marginarea 21, three sync-blocks of a preamble area 22, four sync-blocks of asub-code area 23, three sync-block of a post-amble area 24, threesync-blocks of an IBG (Inter Block Gap) area 25, one sync-block of apreamble area 26, 336 sync-blocks of a main code area or a data area 27,two sync-blocks of a post-amble area 28 and a margin area 29. The maincode area 27 and the sub-code area 23 are provided for a recording areaof information.

In addition thereto, a rotating member mounted with the rotary head 2 iscontrolled so as to rotate at 30 rps or 29.97 rps by a drum servosystem, so that the margin area 29 is composed of two sync-blocks or2.356 sync-blocks. Accordingly, one track is totally composed of 356sync-blocks or 356.356 sync-blocks. In any cases, the sub-code area 23and the main code area 27 are assigned to be a fixed length of foursync-blocks and 336 sync-blocks respectively. In the main code area 27,188 bytes per each packet of a MPEG2 transport stream is recorded in aunit of two sync-blocks, which are adjacent to each other.

FIG. 3 shows an exemplary format of a sync-block in the main code area27 shown in FIG. 2.

A typical format of a sync-block allocated in the main code area 27 outof each sync-block mentioned above is shown in FIG. 3. In FIG. 3, onesync-block comprises two bytes of a sync-signal (Sync) area 31 forreproducing the sync-block, three bytes of an address information (ID)area 32, two bytes of a main header storage area 33 for containingvarious information, one byte of a data auxiliary (Data-AUX) area 34, 96bytes of a data storage area 35 and 8 bytes of a inner parity storage(Inner Parity) area 36 for correcting error of the sync-blockinformation. These areas are constituted in time series and composed of112 bytes totally. Further, the main header area 33, the Data-AUX area34 and the data storage area 35 configure 99 bytes of a data area. Afirst three bytes composed of two bytes of the main header storage area33 and one byte of the Date-AUX area 34 out of 99 bytes of the data areais an information recording area, which can not be rewritten by a user,and a second 96 bytes is the data storage area 35 of information.

FIG. 4 shows a configuration of flags allocated in two bytes of the mainheader storage area 33 shown in FIG. 3. In the main header storage area33, as shown in FIG. 4, a format information is allocated and recordedin four bits of a high-order half of a first byte, and a sync-blockinformation is allocated and recorded in total 12 bits composed of fourbits of a lower-order half of the first byte and a second byte.

In FIG. 4, a “Format ID” shows whether a track format is a normal moderecording or other mode recording. An “Application Detail” is aninformation utilized for discriminating whether a digital signal to berecorded is an MPEG2 transport packet in 188 bytes of packet size orother packet by other transmission system in 140 bytes of packet size. A“Time Compression Ratio” is an information for showing a compressionratio. Further, a “D.T.” is two bits of a data type information utilizedfor discriminating if a data is an MPEG packet, a dummy data or a trickplay data. An “S.B.C.” is a sync-block counter information utilized fordiscriminating whether a sync-block having a inherent main header is afirst sync-block out of adjoining two sync-blocks or a second while twosync-blocks of which packets are adjacent to each other are recorded asa unit. Further, an “SB No.” represents a sync-block number, wherein “n”in the “SB No.” column is a natural number. Furthermore, “CGMS” and“OPC” represent the “Copy Generation Management System” and an “outputcontrol information” respectively as mentioned above.

In a recording track of the magnetic tape 1 reproduced by thereproducing apparatus according to the embodiment of the presentinvention, an OPC information in conjunction with a CGMS information isrecorded in the main header storage area 33 shown in FIG. 3 beingexisted in each sync-block of the main code area 27 in FIG. 2. Actually,as shown in FIG. 4, two bits of high-order first and second bits of amain header being recorded in the main header storage area 33 of aneleventh sync-block in a first period out of main headers, which arerepeatedly recorded by a unit of 12 sync-blocks in the main headerstorage area 33 by two bytes each, is allocated to a copy generationcontrol signal prescribed by the CGMS standard. Further, two bits ofhigh-order third and fourth bits of a main header, which are recorded inthe main header storage area 33 of a twelfth sync-block in the firstperiod, is allocated to an OPC information.

A first bit of two bits of OPC information shows a permissioninformation of a digital output, “0” represents permission and “1”represents prohibition. Further, a second bit of the two bits of OPCinformation shows a format of analog output, “0” represents “only anoutput of NTSC composite video signal” and “1” represents “permittingcomponent output”. As mentioned above, two bits of a copy generationcontrol signal prescribed by the CGMS standard is as follows: “00”represents “permit to copy or permit dubbing recording”, “10” represents“permit to copy once or permit dubbing recording once” and “11”represents “prohibit to copy or prohibit dubbing.

Referring back to FIG. 1, by two rotary heads having different azimuthangles respectively, which are mounted on a rotating surface of a rotarymember (not shown) with facing toward each other at an angle of 180degrees, although just one rotary head 2 is illustrated in FIG. 1, adigital signal is reproduced from a recording track of the magnetic tape1, which is wound diagonally around an outer surface of the rotarymember over an angle range of approximately 180 degrees and runs in aconstant velocity. The reproduced digital signal is amplified by thehead amplifier 3, added with a predetermined equalization characteristicby the equalizer 4 and demodulated by the demodulator 5, and then errorof data reproduced from the data storage area 35 is corrected by the ECCcircuit 6 by using an ECC, which is reproduced form the inner paritystorage area 36 or the main code storage area 27.

While an MPEG2 transport stream is taken out from the ECC circuit 6 andsupplied to the D. I/F (digital interface) 7, the MPEG2 transport streamis supplied to the MPEG decoder 8 and demodulated. A control information(CTL), which is contained in the main header area 33 shown in FIG. 3, istaken out from the ECC circuit 6 and supplied to the output controlcircuit 9 being controlled by a micro computer, wherein the outputcontrol circuit performs various controls. However, in a case that thefirst bit of the OPC information is “0”, the D. I/F 7 is enabled and theinputted MPEG2 transport stream is outputted as it is. In a case thatthe first bit of the OPC information is “1”, the D. I/F 7 is disabledand outputting the inputted MPEG2 transport stream is prohibited.

Further, in a case that the second bit of the OPC information is “0”,the output control circuit 9 turns the switch circuit 11 off andprohibits an analog component signal from the MPEG decoder 8 to output.On the other hand, in a case that the second bit of the OPC informationis “1”, the output control circuit 9 turns the switch circuit 11 on andmakes an analog component signal from the MPEG decoder 8 output throughthe switch circuit 11.

Furthermore, an analog component signal from the MPEG decoder 8 issupplied to the NTSC encoder 10, wherein the analog component signal isconverted into a color video signal of the NTSC system, that is, ananalog composite signal and outputted. Accordingly, in a case that thesecond bit of the OPC information is “1”, both the analog componentsignal from the MPEG decoder 8 and the analog composite signal from theNTSC encoder 10 are permitted to output.

If an information recorded in the magnetic tape 1 is an HD signal inhigh definition, in a case that the second bit of an OPC information is“0”, only a down converted NTSC composite signal is outputted from theNTSC encoder 10. In a case that the second bit of the OPC information is“1”, an HD component signal from the MPEG decoder 8 and an NTSCcomposite signal from the NTSC encoder 10 are outputted respectively.

In addition thereto, with respect to controlling operation in areproducing apparatus of the copy generation control signal prescribedby the CGMS standard, it is depicted in the Japanese Patent Laid-openPublication No. 11-101178/1999 and 11-319955/1999 filed by the sameapplicant as that of the present invention. Therefore, its detailedexplanation is omitted.

Accordingly, in this embodiment, an output format can be selected by anOPC information in accordance with an intention of a copyrighter, sothat copyright can be more effectively protected. Further, anothercopyrighter having a different intention for an outputting signal formatcan also utilize a recorded software, which can be reproduced in a sameformat by a same reproducing apparatus, so that various high qualitypictures can be enjoyed.

Second Embodiment

FIG. 5 shows an exemplary format of a transmission signal according to asecond embodiment of the present invention. In FIG. 5, an MPEG2transport stream comprises a plurality of transport packets. Eachtransport packet is composed of 188 bytes and comprises eight bits of async-byte area, one bit of an error indication area, one bit of a unitstart indication, one bit of transport packet priority area, 13 bits ofPID (Packet Identification) area, two bits of scramble control area, twobits of adaptation field control area, four bits of circulating counterarea, an adaptation area and a payload area 40.

In the first embodiment mentioned above, it is depicted that an OPCinformation and a copy generation control signal prescribed by the CGMSstandard are allocated and recorded in the main header area 33 of arecording track. However, in this second embodiment, the payload area 40allocated in a transport packet constituting a commonly known MPEG2transport stream as shown in FIG. 5 is recorded with at least an OPCinformation and reproduced.

In other words, a digital signal, which is modulated by a predeterminedsystem such as the NRZI (non-return to zero inverted), is generatedafter the transport packet is converted into a signal by a unit of async-block in a predetermined format. The digital signal is recorded inthe main code area 27 on a recording track of a magnetic tape by using arotary head, and then the magnetic tape is reproduced. In this case, itis a matter of fact that a certain information is recorded so as for areproducing apparatus to identify that an OPC information not a data isrecorded.

While the invention has been described above with reference to specificembodiment and method thereof, it is apparent that many changes,modifications and variations in the arrangement of equipment and devicescan be made without departing from the invention concept disclosedherein. For example, the first and the second embodiments mentionedabove are depicted with referring to a digital VTR. However, the presentinvention is not only limited to a digital VTR but also applied to anyapparatus reproducing a recording medium such as an optical disk otherthan a magnetic tape. Further, a medium can be applied to a transmissionline as well. The transmission line is not only limited to a wireless orwired transmission line but also can be applied to a signal or atransmission data itself, which is transmitted to a computer or otherequipment in a signal format shown in FIGS. 6 and 7.

Third Embodiment

With referring to FIGS. 6 and 7, a receiving apparatus, which receivesan information signal, that is, a transmission data transmitted througha digital broadcasting transmission line and reproduces, is depictednext.

FIG. 6 shows PMT (Program Map Table) syntax in accordance with the MPEGsystem standard.

FIG. 7 shows syntax of an OPC descriptor to be transmitted according toa third embodiment of the present invention.

Almost all video and audio signals transmitted through a digitalbroadcasting are formed in a configuration of a transport streammentioned above and transmitted in conjunction with various informationdescriptors. An OPC information of the present invention can betransmitted through a transmission line such as broadcasting bytransmitting it being included in a payload area of a transport packet,which constitutes an MPEG2 transport stream.

In this embodiment, various information descriptor areas in a payloadarea receive a transmission data, which multiplexes the OPC information,as a signal format for easier handling by such a digital broadcasting.The MPEG2 transport stream standard defines a private descriptor, whichcan be utilized by a broadcaster, as well as some essential descriptorssuch as an identification information. The private descriptor istransmitted through a descriptor “50”, for example, in the PMT of theMPEG2 transport stream shown in FIG. 6.

In FIGS. 6 and 7, “bslbf” means that a transmission data is transmittedin an order of left side bit first and “unimsbf” means that atransmission data is transmitted in sequence from the MSB. “rpchof”(reminder_polynomial_coefficients highest_order_first) means thatcoefficients generating in a generative polynomial of an ECC CRC (cyclicredundancy check) are transmitted in sequence of highest order first. Inaddition thereto, details of a syntax of PMT is depicted in thereference, ISO/IEC 13818-1/ITU Rec.H.222.0: 1996 (InformationTechnology—Generic Coding of Moving Pictures and Associated AudioInformation Part 1: Systems). Therefore, further details of the syntaxare omitted.

Syntax of an OPC descriptor, which transmits an OPC information in thisembodiment, is shown in FIG. 7. In FIG. 7, a descriptor tag(descriptor_tag) is a syntax defined by the MPEG standard and aninformation utilized for specifying a type of the descriptor in eightbits. A descriptor length (descriptor_length) indicates a length of adescriptor in succeeding fields in eight bits. Further, a digital outputcontrol flag (digital_output_control_flag) succeeding seven bits ofreserved area is composed of one bit. In a case of “0”, it is permitted.In a case of “1”, it is not permitted.

Further, a system information loop length (system_info_loop_length)indicates that a system ID is transmitted as many as a number of looplengths. Furthermore, an analog output control flag(analog_output_control_flag) is composed of one bit and indicates a typeof analog output format. In a case of “0”, it indicates that only anNTSC composite video signal is permitted to output. In a case of “1”, itindicates that component is permitted to output.

A system identifier (system_identifier) describes a system beingpermitted to output a digital output in eight bits. It is assigned thatthe “0×01” of a 256 stage in the eight bits indicates, for example, theIEEE 1394 system and the “0×02” and “0×03” indicate another systems “A”and “B” respectively. In a case that only a digital signal prescribed bythe IEEE 1394 system standard, hereinafter called a 1394 digital signal,is permitted to output, the system_info_loop_length is set to “1” andthe eight bits of the system_identifier is described by one systemidentifier signal of “0×01”, and then the 1394 digital signal istransmitted.

A configuration of a receiving apparatus in accordance with thisembodiment can be realized such that a commonly known receiving sectionfor a digital broadcasting signal is installed instead of the magnetictape 1, the rotary head 2 and the head amplifier 3 shown in FIG. 1. Abase band signal of a desired broadcasting station is tuned in and downconverted by the receiving section. Accordingly, the receiving apparatuscan be realized.

Furthermore, an OPC information is not only limited to two bits but alsoa plurality of bits such as three bits or more. It is also applicablethat in a case of four bits, an output format can be assigned in 16states such as “0000” through “1111”. In a case of “0000”, for example,a 1394 digital signal and an analog component signal are permitted tooutput. In a case of “0001”, a 1394 digital signal is prohibited tooutput and an analog component signal is permitted to output. In a caseof “0010”, a 1394 digital signal is permitted to output and an analogcomponent signal is prohibited to output. In a case of “0011”, a 1394digital signal is permitted to output and an HD analog signal isprohibited to output, or the like.

In addition thereto, selection of outputting video information isexplained in the above-mentioned embodiments. In a case of selection ofoutputting audio information, for example, a flag utilized for selectingwhether the audio information is outputted as a digital audio signalcomposed of 48 kHz of sampling frequency and more than 16 bits of bitsper sample or outputted as a digital audio signal composed of less than48 kHz and less than 16 bits can be allocated in the main header area33.

According to the aspect of the present invention, in an apparatus forreceiving or reproducing transmission information, a signal format to beoutputted by an outputting apparatus can be designated in accordancewith the above-mentioned flag to be inputted in conjunction withtransmission information when the transmission information is convertedinto more than one signal format and outputted, so that the transmissioninformation can be processed to be outputted in a certain signal format,which is intended by a copyrighter of the transmission information.Accordingly, another copyrighter having a different intention for anoutputting signal format can utilize a recorded software, which can bereproduced in a same format by a same reproducing apparatus, or canreceive and reproduce a broadcasting signal by a same receivingapparatus. Compatibility of protecting copyright properly in accordancewith an intention of a copyrighter and providing reproductioninformation such as various high quality pictures can be realized, sothat the present invention is extremely useful for industrialapplications.

1. A reproducing method comprising a step of converting a videoinformation, which is reproduced from a recording medium recorded with adigital signal including at least said video information as aninformation, into more than one of a plurality of signal formats beingdifferent from each other and outputting said video information inrespective signal formats, said reproducing method further comprisingsteps of: extracting a flag from said recording medium, wherein saidflag selectively designates an output signal format of said videoinformation whether or not resolution of said video signal is limited toless than a predetermined resolution that is lower than originalresolution of said video information in the step of outputting;controlling said output signal format of said video information to be anoutput signal format designated by said extracted flag.